Stubborn muddy waters flowing out of Emigrant Lake
ASHLAND — Dirty water is slowly settling out of Emigrant Lake four months after an intense February storm roiled the reservoir, but it's still spewing turbid water into irrigation canals and Bear Creek, much to the surprise and dismay of water-watchers.
Tests show Emigrant's surface is starting to clear, drawing wakeboarders, swimmers and paddlers back to this popular recreation and irrigation lake southeast of Ashland, but water off the bottom near Emigrant Dam's outflow port has measured more than eight times dirtier than the surface.
The clay particles sluiced off the bottom during immense inflows Feb. 7 appear to be just slowly sinking, leaving persistently dirty outflows that are rough on Bear Creek's wild salmon, which are already struggling from the drought, while leaving head-scratching water managers wondering when the reservoir will finally settle down.
"It's crazy," says Jim Pendleton, manager of the Talent Irrigation District, which owns the lion's share of the system's water. "Things are trending better (in the reservoir), but it's not showing any real change in the outflows.
"I wouldn't have thought it would last this long," Pendleton says.
During the Feb. 7 storm, water cascaded down the upper stretches of Emigrant Creek and tributaries such as Tyler Creek, adding mud to the flows as it washed out lower portions of Tyler Creek Road.
Flows peaked into Emigrant Lake at nearly 6,000 cubic feet per second, or 10 times what the maximum outflow can be. The lake rose 11 feet over four days as water churned up silt from vast mudflats exposed from the winter's drought-like conditions, turning the lake into the chocolate-brown color that largely has remained.
The dirty water is likely harming feeding patterns and adding stress to already taxed infant wild steelhead in Bear Creek, "but I don't think it's directly killing fish now," says Dan VanDyke, the Oregon Department of Fish and Wildlife's Rogue District fish biologist.
"It's adding to the stress of the most urbanized sub-basin within the Rogue (River Basin)," VanDyke says. "Hopefully, they'll pull through it."
The turbid conditions so far have been considered an anomaly by Pendleton and officials at the federal Bureau of Reclamation, who say they aren't prepared to alter the dam's outflow structure to minimize turbidity during dirty-water summers such as this.
Things could be different had Emigrant Dam been fitted with a multiport release system to suck water from different strata in the lake. But that retrofit came in the late 1950s, when such practices were not common.
If TID could now release surface water, the outflows into Emigrant Creek and to TID canals could be about one-fifth as dirty as they were this week, water records show.
Multiport towers for water releases normally are crafted to control the temperature of outflows, such as the 12-port tower used to dial in Lost Creek Lake releases into the upper Rogue River to be as wild salmon-friendly as possible.
But retrofitting Emigrant Dam with such a capability to control sediment has not surfaced within the bureau as a possible project, regional manager Douglas DeFlitch says.
While the bureau is under federal rules for minimum flow releases from Emigrant to aid wild salmon in the Bear Creek Basin, it has no turbidity or temperature requirements.
"It's not really been on our radar for a multiport (tower)," DeFlitch says. "I don't know what the costs are, but it's probably going to be pretty expensive.
"I don't know what it would take to deal strictly with sediment," DeFlitch says.
The city of Ashland faced a somewhat similar dilemma in the mid-1980s when it tried to find a way to optimize the quality of water released from Reeder Reservoir into the city's water-treatment plant.
In November 1986, the city added a three-port tower to generate the mix of temperature, alkalinity and turbidity for optimal treatment at the plant, improving efficiencies and curbing maintenance costs, says Pieter Smeenk, an engineer in the city's public-works department.
That retrofit cost $200,000, which Smeenk estimated at about $470,000 in today's costs.
Pendleton says he doesn't see a retrofit penciling out at Emigrant, especially when suspended sediment loads such as the current conditions are rare in the summer.
"At least, to date, it's been sporadic," Pendleton says.
"I think everybody's doing their due diligence on it, but there's not much anybody can do," Pendleton says.